The administration of medicaments directly to the lungs is accomplished mainly by two means: (a) pressurized aerosol devices, popularly known as the "inhalers" and, (b) nebulizers, or devices for generation of fine mist of medications. The former has the general advantage of being small and therefore easy to carry in a pocket and readily available for use in emergencies. However, most of them suffer from the main drawback of needing very exacting technique in using them. This makes such "inhalers" almost impossible for the very young or the very old patients and some others with problems with hand-mouth coordination. The nebulizers, on the other hand, are easy to use but suffer from the drawbacks of being large and cumbersome and expensive. In addition, they use solutions of medications in water and thus, some important medications, such as the steroids which are not water soluble, cannot be used in such nebulizers.
The present invention proposes to solve the noted problems of these two main types of inhaling devices. In doing so, an attempt is made to produce a "cloud" in a small, portable, hand held chamber. Since the "cloud" remains in the chamber and is available whenever the user wants to inhale and does not discharge from the device under significant pressure, the main drawback of the hand held inhalers is avoided. Also, because a "cloud" can be seeded using a powder selected from either water soluble or water insoluble medications, or a mixture thereof, virtually all medicines can be administered by this proposed device. Some of the other advantages of the present invention will become apparent as further details are described.
Cloud formation occurs in nature when certain atmospheric conditions are satisfied. The critical conditions are low atmospheric pressure, high humidity, somewhat low temperature, and a critical "seeding" provided in the atmosphere by the ever present particles of dust. All the above conditions come together in the higher reaches of the atmosphere, usually when sufficient humidity prevails, as the other conditions are always present at such heights. However, even at sea level clouds can form as evidenced by fog which occurs when the sum total of factors are favorable, i.e.: when enough humidity meets sufficiently cold temperature in the presence of dust. It is clear then, that with some effort, similar conditions can be reproduced in a gadget to capture this "cloud" for the general purpose of dispensing medications to the airways, and such a desirable achievement would be novel, unobvious, and useful for it would represent a great step forward in the art.
In the present invention, the above variables are brought together in a portable, hand held device in a manner conducive to the formation of a dense cloud "on demand". The steps in carrying out this process include, in sequence, rarefaction of a small air tight transparent chamber by the use of an extracting pump of sufficient power, provision of water vapor by a heating element vaporizing a small quantity of either water or saline solution, and, finally, by the introduction of small quantities of "dust" into this assembly of strategic conditions. The "dust" includes a few micro-grams of finely powdered medicine therein.